/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cassandra.stargate.transport.internal.messages;

import io.netty.buffer.ByteBuf;
import io.stargate.db.Result;
import java.util.concurrent.CompletableFuture;
import org.apache.cassandra.stargate.transport.ProtocolVersion;
import org.apache.cassandra.stargate.transport.internal.CBUtil;
import org.apache.cassandra.stargate.transport.internal.Message;

public class PrepareMessage extends Message.Request {
  public static final Message.Codec<PrepareMessage> codec =
      new Message.Codec<PrepareMessage>() {
        @Override
        public PrepareMessage decode(ByteBuf body, ProtocolVersion version) {
          String query = CBUtil.readLongString(body);
          String keyspace = null;
          if (version.isGreaterOrEqualTo(ProtocolVersion.V5, ProtocolVersion.DSE_V2)) {
            // If flags grows, we may want to consider creating a PrepareOptions class with an
            // internal codec
            // class that handles flags and options of the prepare message. Since there's only one
            // right now,
            // we just take care of business here.

            int flags = (int) body.readUnsignedInt();
            if ((flags & 0x1) == 0x1) keyspace = CBUtil.readString(body);
          }
          return new PrepareMessage(query, keyspace);
        }

        @Override
        public void encode(PrepareMessage msg, ByteBuf dest, ProtocolVersion version) {
          CBUtil.writeLongString(msg.query, dest);
          if (version.isGreaterOrEqualTo(ProtocolVersion.V5, ProtocolVersion.DSE_V2)) {
            // If we have no keyspace, write out a 0-valued flag field.
            if (msg.keyspace == null) dest.writeInt(0x0);
            else {
              dest.writeInt(0x1);
              CBUtil.writeAsciiString(msg.keyspace, dest);
            }
          }
        }

        @Override
        public int encodedSize(PrepareMessage msg, ProtocolVersion version) {
          int size = CBUtil.sizeOfLongString(msg.query);
          if (version.isGreaterOrEqualTo(ProtocolVersion.V5, ProtocolVersion.DSE_V2)) {
            // We always emit a flags int
            size += 4;

            // If we have a keyspace, we'd write it out. Otherwise, we'd write nothing.
            size += msg.keyspace == null ? 0 : CBUtil.sizeOfAsciiString(msg.keyspace);
          }
          return size;
        }
      };

  private final String query;
  private final String keyspace;

  public PrepareMessage(String query, String keyspace) {
    super(Message.Type.PREPARE);
    this.query = query;
    this.keyspace = keyspace;
  }

  @Override
  protected CompletableFuture<? extends Response> execute(long queryStartNanoTime) {
    CompletableFuture<Result.Prepared> future =
        persistenceConnection().prepare(query, makeParameters(keyspace));
    return future.thenApply(ResultMessage::new);
  }

  @Override
  public String toString() {
    return "PREPARE " + query;
  }
}
